In a known wire body processing structure in the related art, a wire body for controlling a working tool attached to the distal end of a forearm extends through the forearm so as to be routed therefrom (for example, see Patent Literature 1). Normally, in this wire body processing structure, if there are a plurality of working tools attached to the distal end of the forearm, a wire body for controlling one of the working tools extends through the forearm, whereas a wire body for controlling the remaining working tools extends outside the forearm.